The association of serum levels of gamma-glutamyltransferase (GGT) with cardiovascular disease risk factors, and with mortality from all causes, cardiovascular disease, and non-cardiovascular diseases, has been examined in a prospective study of 7,613 middle-aged British men followed for 11.5 years.

GGT levels were strongly associated with all-cause mortality, largely due to a significant increase in deaths from ischemic heart disease and other non-cardiovascular disease causes, i.e., non-cancer deaths, in the top quintile of the GGT distribution.

No association was seen with cancer mortality.

When examined separately by the presence or absence of preexisting ischemic heart disease, the increased risk of ischemic heart disease mortality was more marked in those with evidence of ischemic heart disease at screening, particularly in those with previous myocardial infarction (RR=1.67,95% CI 1.03-2.69 ; n=84 deaths).

The increased risk of other non-cardiovascular disease deaths was only seen in men without preexisting ischemic heart disease, largely due to an excess of hepatic cirrhosis.

In summary, many factors other than alcohol intake are associated with increased levels of GGT, in particular body mass index, diabetes mellitus, and serum total cholesterol.

The biologic significance of raised GGT in men with preexisting ischemic heart disease merits further study.